Developer Tools
Handy developer utilities — JSON, Base64, JWT, hashing, UUIDs, regex, diffs, and format converters — all running locally in your browser, nothing uploaded.
All developer tools
JSON Formatter
Paste raw JSON and get it neatly indented, minified, or validated — entirely in your browser, with a clear error message pointing to anything invalid.
Open toolBase64 Encoder / Decoder
Encode any text to Base64 or decode it back, instantly and locally — with full Unicode and emoji support, and nothing ever leaving your browser.
Open toolUUID Generator
Create one or many version-4 UUIDs for IDs, keys, and test data — generated securely on your device with the Web Crypto API, ready to copy in bulk.
Open toolEpoch / Timestamp Converter
Convert a Unix timestamp to a date and back, in seconds or milliseconds, with ISO, UTC, and local formats shown side by side. Runs in your browser.
Open toolPassword Generator
Generate secure random passwords with your choice of length and character sets, using your browser's Web Crypto API — nothing is ever sent anywhere.
Open toolRandom String Generator
Generate random strings at any length from the character sets you choose — lowercase, uppercase, numbers, symbols — copy them one at a time or all at once.
Open toolHash Generator
Compute cryptographic hash digests of any text with SHA-1, SHA-256, SHA-384, and SHA-512 — locally, using your browser's built-in Web Crypto API.
Open toolJWT Decoder
Decode a JSON Web Token to read its header and payload claims in a readable format — locally in your browser, with no signature verification.
Open toolURL Encoder / Decoder
Encode text so it's safe to drop into a URL, or decode percent-encoded text back to readable form — instantly and entirely in your browser, nothing uploaded.
Open toolColor Converter
Convert a color between HEX, RGB, and HSL, with a live swatch preview and one-click copy — paste any of the three formats.
Open toolText Diff
Compare two blocks of text line by line and see exactly what was added, removed, or left unchanged — a quick side-by-side diff that runs in your browser.
Open toolJSON Diff
Compare two JSON objects and get a clear list of the fields that were added, removed, or changed — with full paths, so you spot every difference at a glance.
Open toolJSON ↔ CSV ↔ YAML
Convert data between JSON, CSV, and YAML in any direction — paste one, pick a target, and copy the result. Runs entirely in your browser, nothing uploaded.
Open toolRegex Tester
Test a regular expression against sample text with live match highlighting, a plain-English breakdown of your pattern, and a cheat sheet to learn from.
Open toolQR Code Generator
Generate a QR code for any text or URL and download it as a sharp SVG or PNG — encoded entirely in your browser, nothing uploaded.
Open toolQR Code Reader
Read a QR code from a photo, a screenshot, or your camera, and see the link, text, or Wi-Fi details it holds — decoded right in your browser.
Open toolBarcode Generator
Generate scannable Code 128, Code 39, EAN-13, EAN-8, UPC-A, ITF-14 and Codabar barcodes, with the check digit calculated for you. Download as SVG or PNG.
Open toolToken Counter
Estimate the token count of a prompt across GPT, Claude, Gemini and Llama, with a likely range and a check on whether it fits your context window.
Open toolMarkdown Preview
Convert Markdown to formatted output as you type — headings, lists, tables, links, and code — with a one-click HTML view. Paste text or open a .md file.
Open toolWeb Playground
Write HTML, CSS, and JavaScript across three panes and watch it render instantly in a sandboxed preview. A fast scratchpad for an idea, snippet, or layout.
Open toolNumber Base Converter
Convert a number between binary, octal, decimal, hexadecimal or any base from 2 to 36, exactly — including 64-bit values that break most converters.
Open tool